This invention relates generally to counter mechanisms and, more specifically, to counter operated control mechanisms. More specifically still, the invention relates to new and improved presettable counter mechanisms of modular design having notable utility in fluid fuel dispensing systems.
Presettable counters have been employed for controlling and terminating the delivery of liquid petroleum products. The presettable counter includes a plurality of number wheels which are connected by a count advance transfer mechanism, such that a higher order wheel automatically moves a single digit or count for each complete revolution of the adjacent lower order wheels. The transfer mechanism is disconnected during manual setting in a manner generally described in U.S. Pat. No. 3,456,877 entitled "Counting Mechanism" to permit individual setting or presetting of each digit wheel from a zero reference position in an additive direction. The counter is then driven in a reverse or substractive manner from the preset position and provides the necessary output when the counter reaches a predetermined referenced count, such as zero.
Typically, the output is provided by releasing a loaded and latched rotatably mounted control member when the predetermined reference is reached. Further, it is conventional to provide for an initial partial release of the control member at a predetermined reference greater than zero as for partially closing a flow control valve and to provide a final complete release of the control member at the zero reference to completely close the valve. Such two-stage closure of the valve is disclosed in the Billeter U.S. Pat. No. 3,057,553, the contents of which is incorporated herein by reference.
It is a principal object of the invention to provide a new and improved presettable counter mechanism of the modular or compartmental type having a new and improved arrangement for controlling the closure of a fuel control valve. Included in this object is the provision of a new and improved latching arrangement for releasably latching a fuel control valve in its fully and partially open positions.
It is a further object of the invention to provide a releasable latching arrangement which securely latches a control member in a loaded position yet requires a relatively small force to trip or release the latch. Further included in this object is the provision of a releasable latching arrangement which is reliable throughout an extended operating life. Still further in this object is the provision for an improved latching arrangement in a presettable counter for providing two-stage closure of a fuel control valve.
It is another object of the present invention to provide a new and improved presettable counter mechanism which provides for a two-stage latch releasing arrangement that ensures closure of a fuel valve at a zero reference regardless of the preset count. Included in this object is the provision of an improved arrangement capable of effecting an adjustable first-stage lock release at an easily adjusted first release count which is greater than the zero reference.
It is still another object of the present invention to provide new and improved means in a presettable counter for variably adjusting the count at which a two-stage releasable latch is released. Included in this object is the provision for an adjustable first-stage release and an independently adjustable second-stage release, which adjustments can be effected in a rapid and facile manner without disassembly of the presettable counter. The adjustable first-stage release includes the advantage of removable inserts in the trip cam associated with a higher order wheel for adjustment of the trip to any digit on the wheel while the second stage release is bidirectionally adjustable to provide greater flexibility of operation and more accurate stopping action at zero.
It is another object of the present invention to provide a new and improved manually presettable counter mechanism of the type described having an interlock arrangement for preventing change of the setting of the individual digit wheels while the control member is loaded preparatory to and during the substractive counting operation. Included in this object is the provision of a preset control interlock which also permits presetting the counter wheels only while the fuel valve controlled by the counter is in a closed position.
It is still a further object of the invention to provide a counter having a new and improved count transfer mechanism for transferring the counts between adjacent number wheels thereof. Included in this object is the provision for a new and improved transfer pinion and locking ring arrangement that assures proper orientation, alignment and inter-engagement therebetween when the counter wheels are conditioned for a counting operation.
Yet another object of the present invention is the provision for a presettable counter of the type described that includes a new and improved sliding pawl array associated with the transfer pinions for optimizing the operating forces acting thereon and assuring accurate reengagement of the pinion after a resetting operation.
A still further object of the present invention is the provision for an emergency stop trip mechanism that assure complete and full actuation of the two-stage closure for termination of fuel delivery irrespective of the position of the fuel control valve.
Other objects will be in part obvious and in part pointed out more in detail hereinafter.
A better understanding of the invention will be obtained from the following detailed description and the accompanying drawings of an illustrative application of the invention.